Ions Isotopes Chapter 11 Section 2 Reminder Atoms

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Ions & Isotopes Chapter 11 Section 2

Ions & Isotopes Chapter 11 Section 2

Reminder… • Atoms have a neutral charge because the # of protons = electrons

Reminder… • Atoms have a neutral charge because the # of protons = electrons

Charge of An Atom • IF… # of protons Brain. POP Ions = #

Charge of An Atom • IF… # of protons Brain. POP Ions = # of electrons the atom becomes an ION • ion – charged particle that forms when an atom or group of atoms gains or loses one or more electrons

Charge of An Atom • If # protons > # electrons = positive charge

Charge of An Atom • If # protons > # electrons = positive charge atom loses electron CATION • If # protons < # electrons = negative charge atom gains electron ANION

Ions CATION (+) • ANION (-) •

Ions CATION (+) • ANION (-) •

Are All Atoms of an Element the Same? • Not Necessarily! – Ions –

Are All Atoms of an Element the Same? • Not Necessarily! – Ions – unequal # of protons and electrons – Isotopes – unequal # of protons and neutrons Brain. POP Isotopes • isotope – atoms with the same number of protons (same element) but with different numbers of neutrons (different masses) • In an isotope: – # of protons always remains the same – # of neutrons changes

Looks of an Isotope Proton Neutron Electron This is a Hydrogen Atom Isotope The

Looks of an Isotope Proton Neutron Electron This is a Hydrogen Atom Isotope The isotope has 2 particles which means it has greater mass.

Properties of Isotopes • each element has a limited number of isotopes that occur

Properties of Isotopes • each element has a limited number of isotopes that occur naturally • isotopes share almost all of the same physical and chemical characteristics • example: oxygen isotopes are colorless, odorless gases at room temperature (physical)

How Can We Tell One Isotope from Another? • each element has a mass

How Can We Tell One Isotope from Another? • each element has a mass number which identifies the isotope of the element. • mass number = protons + neutrons in an atom • mass numbers are typically not found on the periodic table

Naming Isotopes Proton Neutron Electron There is 1 proton and 0 neutrons so the

Naming Isotopes Proton Neutron Electron There is 1 proton and 0 neutrons so the name of this atom is Hydrogen-1 Electron There is now 1 proton AND 1 neutron so the name changes to Hydrogen-2

Atomic Mass vs Mass Number Atomic Mass • atomic mass – the average mass

Atomic Mass vs Mass Number Atomic Mass • atomic mass – the average mass of an atom – average takes into consideration all isotopes for an atom – decimal because it is an average of masses Mass Number • mass number – the sum of the numbers of protons and neutrons in the nucleus of an atom – whole number because it is the exact summation of protons and neutrons – rounded atomic mass